A TAXONOMIC REVISION OF COUSINIA CASS., SECT. ALBIDAE BUNGE (ASTERACEAE) IN THE FLORA OF IRAN

Description of sect. Albidae Bunge (Cousinia Cass., Asteraceae) is completed based on new data. Five new endemic species belonging to sect. Albidae Bunge are described and photographed. Cousinia bazoftensis, C. assadii, C. yasujensis, and C. oshtorankuhensis are allied to C. archibaldii, C. oligocephala, C. bachtiarica, and C. albida respectively. Among new taxa C. atrobracteata from Azerbaijan province seems to be an isolated species, based on the morphological characters and geographical distribution, and does not have any distinct related species. Cousinia ottonis Bornm. is considered as a new synonym of C. eburnea Bornm. Description of sect. Albidae is completed. A diagnostic key is provided for the section. The species of sect. Albidae have very restricted distribution "exception C. bakhtiarica, C. oligocephala and C. albescens" and can be regarded as vulnerable and endangered species.